Tracking mechanism for automatic musical instruments



Sept. 23, 1924.

E. G. NICHQLSON TRACKING MECHANISM FOR AUTOMATIC MUSICAL INSTRUMENTS l m QE s n m i 2 w w w M Nu Q m w m g m A 4. 1: F m m m u u c H.M H H W WI G wm wmhuhl U f U 0 O F 5 Q m Q I w\ m N w a LT n y m C 10 0 U if. m m a N N :H

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Sept. 23, 1924. 1,509,765

E. G. NICHOLSON TRACKING MECHANISM FOR AUTOMATIC MUSICAL INSTRUMENTS Filed Dec. 4, 1923 2 Sheets-Sheet 2 Patented Sept. 23, 1924.

UNITED STATES PATENT OFFICE.

ERNEST GOODALL' NICHOLSON, OF SOUTH EALING, LONDON, ENGLAND, ASSIGNOR TO THE AEOLIAN COMPANY, LIMITED, OF LONDON, ENGLAND. l

TRACKING llllIECHANISM FOR AUTOIVIATIC MUSICAL INSTRUMENTS.

Application filed December 4, 1923. Serial No. 678,492.

To all whom it may concern.

Be it known that, I, EnNnsT GOODALL NICHOLSON, a subject oi? the King of Great Britain and Ireland, residing at 2 Badbourne Avenue, South Ealing, London, W. 5, England, have invented certain new and useful Improvements Relating to Tracking Mechanism for Automatic Musical Instrumerits, of which the following is a spec-iii cation.

This invention relates to automatic musical instruments operating under the control. of a tune sheet and provided with means whereby lateral deviation of the tune sheet is automatically overcome by readjustment of the tune sheet in relation to the tracker bar, so that the alignmentof the perforations in the tune sheet with the note ducts in the tracker bar is automatically maintained. Themeans which have been proposed for this purpose, consist, among others, in the provision of two pairs of control ducts in the tracker bar in positions corresponding to two widths of tune sheet, so that when the tune sheet is disposed normally with respect to the note ducts in the tracker bar, thesaid pairs of ducts or the inner pair of ducts respectively, according to the width of the tune sheet in use, are covered, but on the tune sheet deviating from the normal position one duct of the pair of ducts corresponding to the width of the tune sheet is uncovered to admit air, whereby primary valves controlling the mechanism are adjusted and determine the operation of the mechanism for the readjustment of the tune sheet in relation to the tracker bar. The ducts of one pair of control ducts are respectively connected to the primary valve casings by passages or conduits fitted with means whereby communication through them may be interrupted as the result of the admission of air through the ducts of the other pair of control ducts.

The present invention is directed to an improvement in such tune sheet adjusting mechanism whereby it is rendered effective in use with tune sheets of standard width,

or of widths greater or less than standard width, or tune sheets which have expanded or contracted in width as the result of climatic or other conditions.

According to the invention the tracker-bar is provided with three or more pairs of control ducts, the ducts of each pair being disposed at a distance apart corresponding to a particular width of tune sheet and each pair serving for a different width of tune sheet, and the said control ducts are adapted to determine the adjustment of primary valves controlling the operation of the mechanism serving to re-establish the normal disposition of the tune sheet with reference to the tracker bar, and are so provided that only that pair of which one is uncovered as the result of lateral movement of the tune sheet is effective to determine the necessary adjustment of the primary valves.

Certain of the control ducts, when uncovered by the tune sheet, are adapted to admit air to one or other of two chambers, cylinders or the like provided with diaphragms,pistons or the like for effecting the movement of the primary valves and for this purpose the ducts of one pair of the control ducts, for example, the pair cor responding to the narrowest width of tune sheet, may be respectively in communication directly with the said chambers or the like, while the ducts of the other pairs either communicate with the said chambers or the like by passages adapted to be interrupted, or serve to admit air by which the interruption of the passages fromthe other ducts is effected. The, control ducts may conveniently be connected with a junction block or blocks formed with chambers or recesses provided with flexible diaphragms, pistons or the like which, upon the admission of air at one side, serve to close or interrupt the passage for air from one of the control ducts to the primary valve chambers or the like.

The mechanism effecting relative movement of the tune sheet and tracker bar under the control of the said ducts conveniently comprises a pneumatic actuating device adapted to move the tune sheet or music roll and the take-up spool in the axial direct-ion by such means as cams. Other means for efi'ecting the relative movement of the tune sheet and/or tracker bar, however, may be provided. 1

The invention further comprises the constructional features hereinafter described and claimed.

The invention is illustrated by way of example in the accompanying drawings.

Figure 1 represents, diagrammatically and in part section, tune sheet adjusting mechanism provided in accordance with the invention.'

Figure 2 is a corresponding plan View. Figure 3 .is an elevation of the junction block to an enlarged scale.

Figures 4: and '5 are respectively sections on the lines rib-fist, B-JB, of Figure 3.

In carrying the invention into effect according to the construction illustrated in the accompanying drawings, a tracker bar a of the usual-construction is provided and there are formed therein in'positions determined by the disposition oi the lateral edges oi? tune sheets b of particular widths, when normally disposed in relation to the tracherban pairs of control ducts c d, e f, g in the pair of ducts 0 (Z being disposed at a greater distance than the pair oiducts c f, while similarlythe ducts c are disposed at a greater distance apart than the ducts g A. Thus, the ports (2 f are adapted to cooperate with a mu sic sheet 01" the standard English widtl'i o f 115% inches while the ports 0 (Z will cooperate witha'sheet which has become expanded in width or is cut to a greater width. Similarly the ports 9 it will co-operate with a music sheet which is out to a reduced width, such as the standard American roll which has a width of 11 inches or with a music sheet wh-ich'has become contracted in width. The control ducts are: connected with a junction block 2' by means of tubes 0 d 6 ,7 9, 7L respectively. The junction-block i is provided with a chamber 2' in -theopposing walls oi which there are respectively formed pairs 01" recesses j, is, Z, or; conveniently of circular form the recesses j iabeing smaller in area than the recesses Z m. The said recesses are separated from the chamber t by flexible diaphragms 7' 7r Z m The tubes 0 (Z are respectively con nected with passages 0 (Z2 in the junction block-i which'open respectively into the re cesses 7' 7; at the centres thereof. The bottom of each of the said recesses is advantageously ot'convex form in cross-section so that the diaphragms 7' 70 under certain conditions may serve to close the outlet orifices of the passages c (F. The diaphragins j 70 are advantageously fitted with pallets 7' 70 The tubes 6 f are respectively connected with passages e f respectively in the junction block 2' leading respectively to the recesses m Z. It will be observed that while the control duct '0 is connected by the tube c to the recess the control duct 6 is connected bythe tube 6 to the recess m and not to the recess Z. Similarly the control duct (Z isconnected to the recess 7: while the duct f is connected to the recess Z. The tubes g 7L1 are respectively connected with passages g 'h iforined in the unction block c'and connected with outlet passages 2' 2' with which the recesses'j a-ndic also communicate by way rece ves oi the passages j The passages i i are respectively connected by conduits n 0? with the casing g of the primary valves 02, o, controlling the operating mechanism for eii ecting lateral movement of the tune sheet in the manner hereinafter described. The chamber 71 is connected by a passage 2' with a conduit leading to the main suction sys tern so that the chamber 2' may be subjected to a vacuum for the purpose of drawing the diaphragms j 70 Z m in directions from the respective recesses.

The primary valve casing g 'is provided with a chamber communicating by a con duit g with the main suction system. At the bottom of the chamberg there are formed recesses of 0 closed by 'diap'hragms' it? 0 and provided with passages by which the respective conduits n 0 may "be put into communication with the saidrecesses n 0". Suitable bleed hole communication betweei'i the recess 01, 0 and the main suction system is also provided as indicated at 1 ii'rFig. 1 of the drawings. The primary valves 71, "0, which are respectively disposed contrally above the diaphragms n 0 are provided with stems n 0" which extend upwardly through clearance passages n 0 if'orined'in the upper plate of-the casing The stems 92 0" also carry valve plates at 0 adapted to seat upon the exterior "of theupper'jplate of the casing g.

The passages 72? 0 are connected respectively through suitable conduits with passages n 0 formed in thecentre board"; of two operating bellows or neumatics r r the movable boards of which are connected together by means of rods r so thatwhen one of the pneumatics r 01'4" closesthe other opens. i

In order to perini tlateral adjustment of the tune sheet bthe tune'slieet'ormusic roll 8 andthe take-up spool zfjar'e each mounted to be laterally movable in tlie""tracl e1bo: c Thus the left hand clutch s of the" tune sheet or music roll sis rotatably fitted upon a longitudinally movable spindles carried in a bearing a on the tracker 100:; while" the right hand clutch s is fixedly mountedhpon the spindle s carrying tliebrake disc and re-roll sprocket wheel and mounted so as to be [longitudinally movable in a hearing bracket a secured to the side oi the tracker boX a Similarly the spindle t of the take up spool 25 is slidably carried within a'loejaring bracketc at the left hand side ofhe tracker box while the clutch t is mounted upon a longitudinally movable spindle t carryingthe driving spii'oclzet wheel "and mounted to slide longitudinally in the tracker box and a bracketufl A vertically disposed spindle *u' is mounted in-the plane of the spindles of the time sheet orniusic roll and the take-up spool in a'fo'otstep hearing u and a bracket a fitted to the'bracket a The said spindle carries fixedly mounted upon it cams s t adapted respectively to engage the extremities of the spindles 8 i The cam s is provided with an arm or lever s which is connected with the movable board of the pneumatic r by means of a rod 1' formed in two parts connected by means of a double threaded nut and lock nuts 1' in order that adjustment of the length many be effected. A spring is connected between the bearing a and a collar upon'the spindle s for the purpose of cansing the tune sheet or music roll to follow the cam a while similarly the spindle t of the take-up spool bears against a leaf spring serving to press the spool in the direction of the cam t.

The operation of the mechanism illustrated in the drawings is as follows:-Assuming that the tune sheet is of a width such that it covers the control ducts 0 d when it is in the normal position and'that both ducts are covered, no air is admitted to the recesses 12 0 of the primary valve casing Q and the valves n 0 remain in the lowermost position so that the bellows r r are subjected to the suction applied at g and remain in the central or neutral position, in balance. When, however, the tune sheet moves so as to uncover the duct 0, air-passes by way of the tube 0 to the recess j of the T junction block a and, since suction is applied to the chamber 7? and the diaphragm j is drawn outwardly from the recess j, the air can passby the passages 7' and i and tube a to the recess n The diaphragm n is therefore lifted under the suction and raises the valve n to cut off the suction from the passage a and to open the said passage to the atmosphere by the lifting of the valve plate n". Air thus passes by the passage n into the bellows T The bellows 1' therefore closes under the suction and operates the cams .9 t through the rod 9* to move the tune sheet or music roll 8 and take-up spool 25 to the left hand so that the tune sheet is returned to the normal position covering the port 0. Similarly when the tune sheet uncovers the control duct d air passes through the path represented by the tube al recess is, passages la and 7?, tube 0 to the recess 0 so that the diaphragm o rises, lifting the valve 0 and admitting air below the valve plate 0 to the passage 0 The bellows r there fore closes and the cams s t are moved to permit a movement of the tune sheet or music roll 8 and take-up spool 15 to the right under the action of the springs s and Z.

In the case of a music sheet of a width corresponding to the spacing of the ducts e f, when the tune sheet is in the normal position the exposure of the ports 0 d does not result in any movement of the mechanism for the reason that air is admitted simultaneously by way of the tubes 0 al through the paths hereinbefore described so that both the diaphragms n and 0 are effective to lift the valves a 0 and thus to place the bellows r and 1' both in communication with the atmosphere so that they remain in balance. lVhen, however, the tune sheet moves laterally and exposes the duct 6, air is admitted by way of the tube 6 to therecess m with the result that the diaphragms m k are thrown over and the admission of air from the passage (l into the recess is is interrupted. The diaphragm 0 in the primary valve box is therefore permitted to fall and with it the valve 0 so that the bellows 1' is subjected through the passage 0 to the suction applied through g to the chaniiber 9 and communication with the atmosphere is interrupted by the fall of the valve plate 0'. Thus the bellows i closes and the tune sheet is moved to the left in the manner before described. Similarly in the case when the tune sheet moves to uncover the control duct the "balance of the bellows W T is de stroyed by the falling of the diaphragm -22 and with it the valven so that the bellows r is subjected through the passage a to the suction applied at g to the chamber 9' and communication with the atmosphere is interrupted by the fall of the valve plate a. The bellows 1- therefore closes and the tune sheet is moved to the right to cover the con-- trol duct in the manner hereinbefiore described.

, In the case where the tune sheet is of a width corresponding to the distance be tween the outer edges of the control ducts g and h and when in the normal position uncovers the control ducts a (Z c and f, the mechanism remains inoperative by reason of the fact that the bellows r r are again in balance. This is due to the fact that the admission of air by both of the ducts e and 7 results in the simultaneous throwing over of the pairs of diaphragms j Z m so that the passage of air through both tubes 0 and (Z to the tubes n and 0 is'interrupted and therefore both the diaphragms n and 0 remain in the lowermost position so that the valves n 0 permit the suction applied at g to act equally through the passages n 0 upon the bellows 1' 1 hen, however, the tune sheet moves laterally to uncover the control duct g, the air admitted passes by way of the tube 9 and the passage g to the tube 71- so that the valve n is lifted and air can pass below the valve plate n into the passage n to the bellows r. The bellows r then closes and the tune sheet is moved to the left again to cover the duct 9. Similarly when the tune sheet moves to the left to uncover the duct it, air passes by way of the tube h to the passage 7L and thence by way of the tube The t lifted to admit air to the bellows 9' bellows r then closes vand the tune sheet is moved to the right again to cove-r the duct 72,. l

It will be understood that the invention is not limited to the particular construction of the parts of the mechanism hereinbefore described and illustrated as these may the clearly varied without departing from the invention Thusthe control ducts may be formed if desired within a separate tracker bar provided especially iorthe purpose. Again; the primary valves a, 0 may serve tocontrol the action of any suitable construction of mechanism having for lts purpose to secure the normal disposition of the tune sheet with reference to the tracker bar.

ll claim:

1. Tracking mechanism for automatic musical instruments operating under the control of a tune sheet and provided with means whereby upon lateral deviation of the tune sheet the exposure of a control duct results in the operation of mechanism serving to re-establish the normal disposition of the tune sheet with reference to the tracker bar, wherein aplurality of pairs of control ducts are provided each pair of which correspondsto a particular width of tune sheet, the said pairs of control ducts being so provided that only'that pair of which one duct is uncovered as the result oi lateral movement or the tune sheet is effective to determine the re-adjustment of the tune sheet with reference to the tracker bar, substantially as described 2. fllraclring mechanism for automatic musical instruments as set forth in claim 1, wherein the ducts of one pair of the con trol ducts directly communicate uninterruptedly with chambers, having diagrams for effecting movement of primary valves substantially as described.

3. Tracking mechanism for automatic musical instruments as set forth in claim l, and having certain ducts of the pair oicontrol ducts in communication with the primary valve chambers by passages adapted to be interrupted upon exposure oi other control'ducts, the said interruption of the passages being nullified upon the exposure of yet other control ducts, substantially as described. 7 I

at. Tracking mechanism for automatic musical instruments as set forth in claim 1 having oppositely disposed chambers fitted with 'diaphragms subjected to suction, one of said chambers ali'ording communication between a duct of one pair of control ducts and a primary valve casing subject to interruption by the corresponding diaphragm, and the other chamber communicatingwith a duct of another pair of control ducts wherein the second of the said chambers is of larger areathan the first andthe corresponding; diaphragm is enabled .to over power the diaphragm of the first chamber on the'admission of air toth'e said second chamber, substantially as described.

runner vso0mm, NICHOLSON. 

